Патент USA US2411356код для вставки
NOV. 19, 1946. B_ P_ BAKER ET AL 2,411,356 VALVE MECHANISM FOR COMPRESSED GAS CIRCUIT INTERRUPTERS ‘Filed March 15, 1943 2 Sheets-Sheet 1 Fig.1. Z5 lnsu/af/on Z3 ' '29 a [/75 (1/0 flan 43 4/ e/ 39 WITNESSESI ” “Z - INVENTDRS 5&0/10/17/0 PBa/rer a?d/Verberffh/eéb. NOV. 19, 1946. a p_ BAKER ET AL VALVE MECHANISM FOR COMPRESSED GAS CIRCUIT INTERRUPTERS Filed March 15, 1945 2 Sheets-Sheet 2 Fig 2. (D I05 1'07 M5 11/ 14/ WITNESSES: § 1% INVENTORS - Ben lam/n FBams'r‘ and ljkvéerflh/ebbk q tiff‘ Q/ATTORNI; Patented Nov. 19, 1946 2,411,356 UNITED ‘STATES PATENT OFFICE 2,411,356 VALVE MECHANISM FOR COMPRESSED GAS . CIRCUIT INTERRUPTERS Benjamin P. Baker, Turtle Creek, and Herbert J. Webb, Forest Hills, Pa., assignors to Westing house Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania ‘ Application March 13, 1943, Serial No. 479,066 10 Claims. (Cl. 137-139) 1 2 The invention relates, generally, to compressed gas circuit interruptersand, ‘more particularly, valve and having a by-pass connection which au-' tomatically directs ?uid under pressure to the to a valve mechanism for controlling the flow of opposite side of the piston at the end of the op erating stroke‘to insure quick closing of the valve. compressed gas to the circuit interrupter. In compressed gas circuit interrupters, it is desirable that the valves operate quickly in re sponse to the operation of the control electro magnets and relays, particularly the blast valve Another object of the invention is the provi sion of an improved valve mechanism embodying a ?uid motor operating means to which ?uid un der pressure is admitted by a relay valve that also functions to quickly exhaust the ?uid pressure 10 in the motor upon closing of the relay valve. The control of the blast valve is usually Another object of the invention is the provision which controls the ?ow of compressed gas to ex tinguish the arc drawn by the interrupting con tacts. closely coordinated with the contact movement, of a compressed gas circuit interrupter with an and it is important that this valve should not improved high speed valve mechanism that is only open quickly but should remain open only very simple, reliable and quick in operation, and so long as is necessary for the current arc to be 15 economical to manufacture. extinguished and should then close very quickly upon deenergization of its control relay in order to prevent wastage of compressed gas. The rate of consumption of compressed gas for each pole, The novel features that are considered charac teristic of the invention are set forth in particu lar in the appended claims.‘ The invention itself both as to structure and mode of operation, to unit of some gas blast circuit breakers is ?ve or 20 gether with other objects and advantages there of, will be best understood from the following de more cubic feet of ‘free gas per 1/60 of a second, and unless the blast valves close quickly as soon as the control relay is deenergized, a consider able quantity of compressed gas will be wasted. The operating forces used to effect high‘ speed movement of the valve to open and closed posi tion are relatively large, and since the available control energy is usually small, it is desirable that tailed description of one embodiment of the in vention when read in conjunction with the ac companying drawings, in which: Figure 1 is a side elevational view of a com pressed gas circuit interrupter embodying the improved valve mechanism of the invention; Fig. 2 is an enlarged sectional view of ‘the im the. force required to initiate operation of the proved valve operating mechanism; and valve mechanism should be kept small. An object of the invention is the provision of a compressed gas circuit interrupter with an im valve assembly. proved high speed valve mechanism which will voltage compressed air circuit interrupter simi_ open and close very quickly in response to ener gization and deenerglzation oi the control device therefor. Another object of the invention is the provision of an improved valve mechanism for a fluid cir cuit interrupter, which is operated at very high speed to valve open and to valve closed positions by a relatively large force and yet which requires only a relatively small control force to initiate operation of the valve. ‘ Fig. 3 is an enlarged sectional view of the The invention is illustrated as applied to a high lar to the circuit interrupter disclosed in the co “ pending application of Leon R. Ludwig et al., Se rial No. 431,394, ?led February 18, 1942, now Pat ent No. 2,394,086, issued February 5, 1946, and assigned to the assignee of the present invention. It is to be understood, however, that the im 40 proved valve mechanism of the present inven tion may be applied to any form of compressed gas circuit interrupter either as a blast valve mechanism or as a valve for controlling the fluid Another object of the invention is the provi sion'of an improved high speed valve mechanism motor which operates the contact means. Referring to Figure 1 of the drawings, the cir operated by a compressed gas motor to which a cuit breaker is mounted on a supporting frame 5 and is insulated therefrom by a plurality of hollow supporting insulators ‘I and 9, only one of relatively large quantity, of compressed gas is quickly admitted for effecting high speed oper ation of the motor and main valve by a com pressed gas operated relay valve that is, in turn, controlled by a pilot valve. ‘ Another object of the invention is the provision of an improved valve mechanism embodying a the insulators ‘9 appearing in this ?gure. A housing ll mounted on the insulators l and 9 contains an operating cylinder [3 and piston [5 for actuating the movable contact member I‘! to open and closed circuit position. The movable contact member ll extends upwardly through a ?uid operated piston to which ?uid under pres sure is admitted for effecting opening of the 55 hollow insulator l9 into the chamber of an arc in-. 2,411,356 3 4 terrupting unit 2| secured on top of the insulator l9. A hollow insulator 23 mounted on top of the interrupting unit is closed at its upper end by a cap 25 having a terminal 21 thereon. A station ary contact member 29 supported by the cap 25 extends downwardlyinto the upperend of thev chamber of the interrupting unit 2| for engagee ment by the movable contact member. and connected to the pipe sections 39 and 43 (Fig. l). Extending through a side portion of the hous ing and journaled therein is a rock shaft 5| hav ing a non-circular portion within the valve hous ing to which is secured a rocker arm 53. Pivotally connected to the rocker. arm 53 within the valve housing is a valve spindle 55. A blast valve ele .ment Bi is connected to the lower portion of the Fluid under pressure, in this instance, com— spindle, and this valve element has a tubular por pressed air, for extinguishing the arc drawn by' tion which slides in a guide 51 formed integral the contact members in the interrupting unit and for the operating ‘means |3——|5 is stored and maintained in a tank 3| mounted within the frame 5, A manifold 33 connected to the tank 3| forms the common air supply for both func with a valve seat 59 secured within the lower tions. . The opposite ends of the breaker operating cyl inder I 3 are connected through-pipes 35 and 3'5, passages of insulators 9 and pipes 38 (only one of which is visible in Fig. 1), to the manifold 33. A pair of electromagnetically controlled valve mechanisms. (not shown) are interposed ‘between the pipes 3.8 and the manifold 33. for controlling the. now of opening and closing air to, the cylinder It to control opening and closing operation of portion of the valve housing. The blast valve element 6| bears tightly against the valve seat ,in the closed position of the blast valve. A yoke shaped crank‘ lever 63 is secured to the end por tions of the rock shaft 5| on the outside of the valve housing, and this crank lever is pivotally connected to the 'valve operating mechanism which is shown in Fig. 2. As has previously been pointed out, it is very important that the blast valvev should open very quickly to its full open position. in response to en'ergization of its control el'ecti‘omagnet.‘ It is. also important that the blast valve should close Extending upwardly from the. manifold 33. is a large diameter section of pipe 3.9 which com. very quickly upon deenergization of its control electromagnet and relay in order to prevent. wastage of compressed air. A considerable oper ating force is. required to quickly open thev valve municates through- a blastv valve 4| and a short against the pressure of the supply air, and yet its. . the circuit breaker. section of pipe 53 with the passage through the. operation must be initiated by relatively small interior of the hollow insulator ‘I. force. since the electrical control energy available The passage of this insulator communicates through a. pipe 45 with the passage through the hollow insulator ii! which, in turn, connects with the chamber of the arc extinguishing unit 2i. When the blast valve 4| opens, ablast of compressed air ?ows from the for control of the valve is usually small. In. ac cordance with the present invention, the blast valve is provided with an improved high speed, operating mechanism which will‘ open and close the valve very quickly and yet requires only a. rel manifold '53 through pipes 3.9, 43, insulator l, atively small force to. initiate the operation of pipe 135, and insulator 59' into the arc. extinguisher the. valve. 2|, where it quickly extinguishes the current are Referring to Fig. 2, the valve operating‘ mech drawn between the. contacts, ll’ and 29. 40 anism comprises an. operating cylinder 65' and When the circuit breaker is. operated to» open. an operating piston 61 reciprocally movable there position the‘ tip of the moving contact member in which is. operatively connected to the crank if. moves downwardly out of the ‘extinguisher 2i lever c3 of the blast valve by’ means of a con necting rod 69' extending through an opening in and continues its movement some distance down into. the space within the hollow insulator iii so a; the top wall of the operating cylinder. A pair of as. to provide an isolating gap. in series with the concentrically arranged helical compression interrupting unit 2 la. springs 'H and, 12 are. disposed within the oper The circuit breaker alsoincludes a. series iso ating cylinder between the operating piston and lating switch (not shown) with a separate com head of the cylinder. These springs encircle a pressed air operating motor therefor which is portion of the connecting rod and serve to bias pneumatically interlocked with the. motor [3,. Li the valve operating piston 61; downwardly to its of the interrupter for sequence operation. and lower limiting position, thereby biasing the blast controlled by the same. opening and. closing con valve 6| to closed position. trol valves, as disclosed’ in the aforementioned The blast .valve is adapted to be operated to copen'dingjapplication of Leon R. Ludwig, et. al., open position by admitting compressed air into SerialNo. 431,394. The disconnecting switch and the lower end of the valve operating cylinder its operating. means have notbeen illustrated and 65 beneath the valve piston 57. A rela'y'valve described in this application since it is unneces assembly, indicated generally at 13, is provided sary for a complete understanding of the present for controlling the ?ow of compressed air to invention 60 and from the. valve operating cylinder 65. This. The blast valve 4| is arranged to be opened relay’ valve 13 comprises a castv housing 15 hav simultaneously with the Opening control, valve ing a pair of air passages Ti and 19- adapted to (not shown) so that a blast, of air is directed to communicate, respectively, with cooperating pas the contacts within the interrupting unit as soon sages Bi and 83 formed in- the cylinder casting as they begin to separate. Thebl'ast valve is pref . 85 of the operating cylinder 65. The relay valve erably arranged to be closed; immediately after includes an inlet valve element 81' which con the arc has beencompletely extinguished, in order trols communication betweenthe passages 11 and to. conserve compressed‘ air. l9to control the-admission of. compressed air into The blast valve mechanism of the present in the lower end of the operating cylinder 65. The vention comprises the blast valve 4| of Fig. 1 O valve. element 81 is mounted on a valve stem 89 which, is. shown in. detail in Fig. 3. and. the im to the top of which is secured an. actuating pis provedhigh speed-operating means therefor which. ton 91. The piston‘ 9|.v is movable in' a cylinder is shown in, detail in‘Fig. 2 of the drawings. provided in the relay valve housing, and. the. Referring to Fig. 3,. the: blast valve» 4| has -a lower portion of. the piston‘ is- formed to-prov-ide housing 49 which. is removably mounted between 75. an exhaust valve 93 engageable with‘. an exhaust. 2,411,356 5 - valve seat at the upper end of the central pas proper position against the casting 85 by means sageway in the valve. An atmosphere exhaust of a plurality of cap screws (not shown). port 95 is formed in the relay valve housing in The passages 11 and ‘I9 and the inlet valve communication with the cylinder portion con element 81 of the relay valve ‘I3 are of relative taining the actuating piston 9|. The exhaust 5 ly large size so that when the relay valve is open, valve portion 93 controls communication between a large quantity of compressed air is admitted the passageway 19 and the exhaust port 95. The into the lower end of the blast valve operating opening in the cylinder portion above the actu cylinder 65 to very quickly actuate the main blast ating piston 9I is closed by the screw cap ‘91. valve to open position. The passages and pilot A helical compression spring 99 is disposed be 10 valve element of the pilot valve assembly are of tween the underside of the inlet valve element 81 smaller size, but such that they pass a sufficient and a screw plug IOI threaded in an opening in quantity of compressed air to the top of the re the valve housing immediately below the valve lay valve operating piston 9| upon opening of element Bl. The spring 99 serves to bias the the pilot valve to quickly effect opening of the relay inlet valve element 81 to closed position 15 relay inlet valve 81. By providing the pneumati against its seat. In this closed position of the cally operated relay valve ‘I3 between the blast inlet valve element 81, the actuating piston 9| valve operating cylinder and the pilot valve, it is in its upper limiting position in which the is possible for the relatively small pilot valve to exhaust portion 93 formed thereon is in open pass sui?cient air to the top of the cylinder in the position. 20 relay valve ‘I3 to open the relay inlet valve 81 The inlet valve element 8‘! of the relay is adapt which, in turn, connects the pressure source to ed to be quickly moved downwardly to open posi the region under the blast valve operating piston tion by admitting compressed air into the upper 67 through a passage which is many times larger end of the cylinder above the actuating piston than Would have been possible by using the pilot 9|. The compressed air drives the piston quickly 25 valve alone for this purpose. By this method a downwardly, opening the inlet valve element 81, large quantity of air is admitted to the blast valve and closing the exhaust valve 93. Compressed air operating piston under the control of a relative is thereupon admitted through the passages 8|, ly small and light pilot valve which requires only a very small operating force. With this construc TI, ‘I9 and 83 into the lower end of the main blast valve operating cylinder 65 for actuating the blast 30 tion it was found possible to reduce the time re quired to obtain full opening of the blast valve valve piston 61 to open the blast valve 6|. to less than two cycles, where prior valve mech Operation of the relay valve is controlled by an electromagnetically operated pilot valve assem anisms required considerably more time to obtain full opening of the blast valve. bly, indicated generally at I03. This pilot valve assembly comprises a small pilot valve housing 35 In addition to opening the blast valve quickly, it is also very important to close it quickly after I05 secured to one end of the relay valve housing interruption of the arc has been accomplished, ‘I5. The housing I05 contains a pilot valve ele and the control relay deenergized, because for ment III‘! for controlling the flow of compressed every cycle that the blast valve remains open air into the upper end of the relay valve actuating cylinder above the relay valve actuating piston 40 after deenergization of its control relay, a very considerable quantity of compressed air‘ is un III. The pilot valve housing is provided with necessarily wasted. The provision of the relative passages I09 and III which communicate, re ly large exhaust valve 93 and exhaust port 95 spectively, with cooperating passages I I3 and H5 in the relay valve 13 quickly discharges the com~ in the right-hand portion of the relay valve hous ing ‘I5. The small pilot valve element I0‘! is is I pressed air under the blast valve operating pis ton '01, thereby permitting very quick closing of biased to closed position against a valve seat II‘! the blast valve. by a small helical compression spring I I9 bearing In order to close the blast valve quickly it would against the underside of the pilot valve element. seem desirable to make the biasing springs ‘II and In this closed position the pilot valve shuts oil communication between the passages I09 ‘and 50 ‘I2 very heavy. However, it is apparent that this would detract from the speed with which the III. The valve element is secured to a valve blast valve could be opened. Since the area of spindle I2I which extends upwardly through an the blast valve operating piston BI is quite large, opening in the valve housing and connects to we have found that even if a small air pressure the movable armature (not shown) of a control ling electromagnet I23 mounted on top of the 55 could be applied to the top side of the operating piston 67, it would greatly facilitate the speed at pilot valve housing. An exhaust valve element which the blast Valve could be closed. In ac I22 on the spindle I2I is arranged to close an cordance with the present invention, very high exhaust port I 24 when the pilot valve element III‘I speed closing of the blast valve is obtained by is in open position as shown in Fig. 2, and to open the exhaust port I24 when the pilot valve element 60 providing means for automatically admitting a quantity of compressed air into the upper end of IU‘I is in closed position thereby discharging com the operating cylinder 05 on the closing side of pressed air above the piston SI and in the passage the valve operating piston 61 at the time the I I3 to atmosphere. The pilot valve I0‘! is adapted blast valve reaches full open position. This air to be moved downwardly to the open position 65 is trapped in the upper end of the operating cyl shown in Fig. 2 upon energization of the electro inder and very materially assists the biasing magnet I23. The passages H5 and III, communicate with the main inlet passage 8| in the casting 85. This springs to drive the blast valve operating piston downwardly to quickly close the blast valve. This automatic admission of compressed air‘ to the castingSS is secured on the ?ange portion of a 70 upper end of the valve operating cylinder 55 when pipe section I21 (Fig. 1) which is in communica the blast valve reaches open position is obtained tion with the air manifold 33, the inlet passage 8| by providing a by-pass passage consisting of a having an enlarged portion I29 which communi tube I3I and a pipe connection I33, connected cates directly with the supply pipe I21. The to the Wall of the blast valve operating cylin relay valve housing ‘I5 is removably secured in 75 der 65, as shown in Fig. 2. The tube I3I iscone ‘ 7 / nected through the pipe Jsec'tionjto the interior of the operating cylinder ‘65 at the upper ‘end 8 surev regulating and check ‘valve I35 into then? per end‘ of theic'ylinder‘65 above'the piston, ?lling thereof, the lower end of "the tube 133i ‘being con the space above the 'piston to a pressure almost nected to the interior of the cylinder at Jan in equal to the‘pressure .below the piston. ‘The parts termediate point. The points of connection of remain ‘in this ‘position until the electroma'gnet the tube to the operating cylinder are so dis I 23 'is deenergized‘by its control relay. Upon ‘de posed that when ‘the blast valve ti is in closed energization of the e'lectromagnet 123, the pilot position and the piston is in ‘its lowermost po valve I101 is ‘returned to closed position, and the sition, both openings of ‘the ‘tube connections relay ,valve actuating piston 9| is thereupon into the cylinder are above ‘the piston. When the 10 moved upwardly by the spring 99 to close the blast valve reaches full open position ‘and the inlet valve=element|81 and open the exhaust'valve operating piston 157 is at the upper end of its element ‘93. ‘The compressed air in the cylinder travel, the loweriopening of the tube IE3! into the space below ‘the blast valve operating piston ‘61 cylinder is below and uncovered by the operat is thereupon quickly discharged to atmosphere ing piston ‘El, and the upper connection of the 15 through the dump valve 193 and exhaust port ‘95 tube is disposed above the piston. vThus, after of the relay valve. The compressed air trapped the blast valve has been completely opened, com above the blast valve operating piston 67, aided pressed ‘air passes from ‘the cylinder space below by the springs ‘H, '12, thereupon 'quickly moves the piston into the space at the upper end of thepiston ‘6'! downwardly to the lower en'd'o'f its the cylinder‘ 65 above the piston, and the pres 20 travel, effecting high speed closing of the ibla's't sure in the upper end‘of the piston becomes al valve‘?l. most equal to the pressure below the piston. A bumper 131 is provided on the top wall of the When the blast valve’ is in this open position, cylinder '65, and a resilient bumper 139 is car very little ‘force is necessary to hold it open, and ried by the central portion of the blast valve op it is, therefore, possible to almost equalize the 25 erating portion 6‘! to absorb thekinetic energy force above and below the blast valve operating of the moving parts at the end of the opening piston. .A check valve £35 is interposed between the tube Bi and the pipe connection l33 to keep the compressed air admitted to the ‘upper end of the operating cylinder 65 from ?owing back into the lower end of the cylinder below the pis~ ton. A spring 138 is provided for biasing the removal and replacement thereof, A screw plug MI is also provided vfor the pilot valve assembly topermit access to be had to the pilot valve ['07 check valve I35 to closed position and this spring serves to control the pressure above and below and its spring I i9. .Insome designs it may be permissible to elim the-main operating piston‘fi‘i when the blast valve BI is in open position. The spring is adjustable inate “the relay valve assembly 13 and ‘connect the pilot valve assembly directly ‘to the fluid motor by means of a screw plug I38. of the blast valve ‘for controlling the flow of Thus by means of the spring 136 and screw plug 138 the differ ential pressure on the main piston may be ad~ justed to the desired value. The air trapped above the operating piston 6”! by the check valve after the piston reaches .the upper end of its travel serves to give the operating piston $5 a large accelerating force toward closed position to quickly close the blast valve “67! upon deenerg-iZa tion of the electromagnet E23 and discharge of compressed air below the blast valve operating piston 6'! to atmosphere through the exhaust port ‘:‘9 of the relay valve. The operation of the blast valve mechanism is , brie?y as follows: Opening operation of the blast valve is initiated in response to energization of the electromagnet I23. Upon energization of the electromagnet I23, the pilot valve Hi‘i is moved to open position, thereby admitting compressed air from the manifold 33 through the passages 81, TI, Ill and M3 to the top of the relay valve op erating piston 9|. Compressed air moves the valve actuating piston 9| downwardly, effecting opening of the inlet valve element 58'! of the re lay valve ‘!3, and at the same time closing the ex~ haust valve element 93. A large quantity of com pressed air is thereupon admitted through the passages iii, '5'! and 83 into the lower end of the blast valve operating cylinder 65 beneath the pis ton 61. Since the piston iii is of relatively large diameter, it is driven at high speed 'to the upper end of its travel, thereby effecting quick opening of the blast valve 8! to its full open ‘position. When the blast valve reaches full open position and the piston 67 is at the u-pper'end of ‘its travel, the opening of the tube I31 into the intermediate portion of the cylinder 65 is uncovered by the piston and compressed air from the cylinder space below the piston passes through the tube 1 3 l ‘pres movement of the blast Valve. ' The screw plugs 9'! and till provide access to the movable parts of the relay valve to permit compressed air to the operating cylinder 65. ‘In thisinstance, however, opening and closing of the blast'valve will ‘not be effected as quickly as when the intermediate relay valve is utilized. While the invention has been disclosed in ac cordance ‘with the provisions of the patent statutes, it is to be understood that various changes ‘may be made in the construction with out departing vfrom some of the essential features of the invention. It is desired, therefore, .thatthe language of the appended claims vshould be con strued as broadly as possible ‘in the light of ‘the prior art. We claim as our invention: 1. In a compressed gas circuit interrupter, ‘a high-speed valve mechanism for controlling the flow ‘of compressed gas to the interrupter com prising a valve movable to open and to closed po sitions, a piston operatively related to said valve and working in ‘a cylinder, means for admitting compressed-gas to one ‘end of said cylinder to ef fect high-speed operation of said piston and valve to open position, and means comprising a by-pass passage communicating with said ‘cylin der and opened by said piston when said valve reaches open position for admitting compressed gas to ‘the other end ‘of "said cylinder to operate said piston‘and valve ‘to closed position. 2. A valve mechanism for controlling ?ow of compressed gas to a circuit interrupter mecha nism comprising, a valve element movable to open and to closed position, a piston connected to said valve element, a cylinder in ‘which said piston is movable, means for admitting compressed gas into one end of said cylinder to effect opening of said valve, element, and means comprising a vby pass passage ‘communicating with said cylinder and opened by said piston adjacent the end of ‘its 2,411,356 10 ' travel in valve opening direction for admitting compressed gas from said one end of said cyl inder into the other end of said cylinder. 3. A valve mechanism for controlling flow of to effect high speed operation of said piston to open said main valve, an exhaust passage for quickly discharging compressed gas from said one end of said cylinder to allow quick closing of compressed gas to a circuit interrupter mecha Cl said main valve, spring means biasing said main nism comprising, a valve element movable to valve to closed position, a by-pass passage com open and to closed position, a piston connected municating with said cylinder disposed to be un to said valve, a cylinder in which said piston is covered by said piston adjacent the end of the reciprocally movable, means for admitting com valve opening travel thereof for admitting com pressed gas into one end of said cylinder to ef 10 pressed gas from said one end of the cylinder into fect opening operation of said valve element, a the other end thereof, and a check valve in said by-pass passage communicating with said cyl by-pass passage operable to cause said compressed inder and disposed to be uncovered by the piston gas to quickly operate said piston and valve to adjacent the end of its travel in valve opening closed position upon opening of the exhaust pas direction to admit compressed gas from said one sage. end of the cylinder into the other end, and a check 8. A valve mechanism for controlling ?ow of valve in said passage. compressed gas to a circuit interrupter mech 4. A valve mechanism for controlling flow of , anism comprising, a valve element movable to compressed gas to a circuit interrupter mech~ open and to closed position, a piston connected to anism comprising a main valve element movable 20 said valve, a cylinder in which said piston is re to open and to closed position, an operating cyl ciprocally movable, means for admitting com inder, a piston in said cylinder operatively con pressed gas into one end of said cylinder to effect nected to said valve element, means for admitting opening operation of said valve element, a vby-pass compressed gas into one end of said cylinder to passage communicating With said cylinder and effect opening of said main valve element, a spring 25 disposed to be uncovered by the piston at a point biasing said main valve element to closed position, near the end of its travel in valve opening direc and a by-pa'ss passage communicating with said tion to admit compressed gas from said one end of cylinder disposed to be uncovered by said piston the cylinder into the other end of said cylinder, during its travel in valve opening direction to ' a check valve in said passage to prevent return admit compressed gas into the other end of said 30 ?ow of compressed air through said passage to - cylinder to operate said main valve to closed posi tion. 5. A valve mechanism for controlling flow of compressed gas to a circuit interrupter compris ing, a main valve movable to open and to closed position, an operating cylinder, a piston in said cylinder connected to said main valve, means for admitting compressed gas into one end of said cylinder to effect movement of said piston to open the main valve, a by-pass passage in communi cation with said cylinder disposed to be uncovered by said piston adjacent the end of its travel to admit compressed gas into the other end of said thereby cause the compressed air admitted through said by-pass passage to quickly operate said piston and valve to closed position, and ad justable spring means biasing said check valve to closed position. ' 9. A valve mechanism for controlling flow of ‘compressed gas to a circuit interrupter mech anism comprising,’ a valve element movable to open and to closed position, a piston connected to said valve element, a cylinder in which said piston > is movable, means for admitting compressed gas into one end of said cylinder to effect opening of said valve element, means comprising a by-pass cylinder, a check valve in said passage, and a passage communicating with said cylinder and passage for exhausting compressed gas from said 45 opened by said piston adjacent the end of its one end of the cylinder and thereby cause the travel in valve opening direction for admitting compressed gas admitted through the by-pass to compressed gas into the other end of said cylin the other end of the cylinder to aid in moving the der, valve means disposed in said by-pass passage, piston to close the main valve. and means biasing said valve means, to provide 6. A high speed valve mechanism for'control 50 differential gas pressure in said ends of said ling flow of compressed gas to a circuit inter cylinder. ' rupter comprising, a main valve movable to open 10. A valve mechanism for controlling ?ow of and to closed position, an operating cylinder, a compressed gas to a circuit interrupter compris piston in said cylinder connected to said valve, a ing, a main valve movable to open and to closed passage for admitting compressed gas into one positions, an operating cylinder, a piston in said end of said cylinder to effecthigh speed movement cylinder connected to said valve, a passage for of said piston to open said main valve, an exhaust ‘ admitting compressed gas into one end of said passage for discharging compressed gas from said cylinder to open said main valve, a by-pass pas one end of the cylinder and thereby allow said sage in communication With said cylinder dis main valve to close, a spring biasing said main 60 posed to be uncovered by said piston adjacent the valve to closed position, a by-pass passage in com end of the valve opening travel to admit com munication with said cylinder disposed to be un~ pressed gas to the other end of said cylinder, a covered adjacent the end of the valve opening check‘ valve in said by-pass passage to prevent travel of the piston to admit compressed gas to return flow of gas from said other end of the ‘the other end of said cylinder to operate said 65 cylinder, means biasing said check valve to con main valve to closed position upon opening of trol the ?ow of compressed gas to said other end said exhaust passage, and a check valve in said of the cylinder, and an exhaust passage effective by-pass passage. when open to quickly discharge the compressed '7. A high speed valve mechanism for control-l gas from said one end of said cylinder to thereby ling ‘flow of compressed gas to a circuit inter 70 cause the compressed gas admitted through said rupter comprising, a main valve movable to‘ open by-pass at the other end of the cylinder to oper and to closed position, an operating cylinder, a ate the piston and‘said main valve to closed po piston in said cylinder connected to said valve, a‘ sition. relatively large inlet passage for quickly admit ting compressed gas into one end of. said cylinder 75 ‘ BENJAMIN P. BAKER. HERBERT J. WEBB.